JPS62101369A - Production of clad ingot - Google Patents

Abstract

PURPOSE:To reduce the production cost of an ingot and to improve the quality thereof by feeding a welding wire to the molten pool in the space between a core material and water cooled mold and pouring a different kind of a molten metal into the molten pool while melting the surface of the core material. CONSTITUTION:The core material 1 is set perpendicularly on a stand 13 and the distance between the water cooled mold 3 and the core material 1 is set at a prescribed value. After a start tab 10 is raised, molten slag 4 is charged into the space between the core material 1 and the mold 3; at the same time, the welding wire 6 is fed thereto. The core material 1 is heated by the Joule heat of the slag 4. The molten metal 15 in a melting furnace 9 is poured into a tundish 7 upon melting of the core material 1 and further the molten metal 5 is poured into the space between the core material 1 and the mold 3. The wire 6 and the molten metal 5 melt and mix with each other and a cladding metal 2 is formed. Since the two metals are combined in the stage of casting, the production cost is reduced the the quality of the ingot is improved.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a clad slab, which is a material for clad steel sheets, in which the surface layer and the inside are made of different metals, each having different properties. be.

(Prior art) Conventional methods for producing clad steel materials include (1) explosion bonding method;
2) Overlay welding method using a band-shaped chamber pole, (3) hot rolling crimping method, (4) cold rolling crimping method, (5) casting method, etc.

All of these methods have advantages and disadvantages, and some problems remain.

Namely.

(1) Explosive bonding is dangerous because it uses the explosive power of explosives to bond dissimilar metals to the base material. Furthermore, since the adhesive is bonded using explosive force, there is a limit to the thickness of the cladding material. Another problem is that the price is high.

(2) In the overlay welding method using a strip electrode, is the welding method horizontal, and submerged arc welding?

Electroslag welding is applied. Therefore, there are problems such as poor productivity and high cost (3) The hot rolling crimping method also has problems such as high cost due to the process 0 (4) The cold rolling crimping method has problems such as high cost etc. It has problems such as limited combinations and difficulty in bonding the interface.

In addition, (5) casting method uses clad material at the casting stage.
A base metal is set, and then molten metal, which will become the base metal or cladding material, is cast to create a clad slab. The interfacial bonding of the boundary is done by blooming rolling, and the amount of molten metal that is poured later is larger than the material (solid phase) that is initially set.
In addition to poor yield, there are problems with interfacial bonding. Additionally, there is a limit to the thickness of the cladding material.

(Problems to be Solved by the Invention) Therefore, it is desired to develop a method for manufacturing clad steel plates at low cost and with perfect interfacial bonding between the clad material and the base material by solving the above-mentioned conventional problems. Ta. From this viewpoint, the present invention provides a method for manufacturing inexpensive, high-quality clad steel sheets.

(Means and Actions for Solving the Problems) The present invention comprises vertically setting a core material having a rectangular horizontal cross section on a pedestal, disposing a water-cooled mold around its outer periphery, and disposing the core material in the gap between the core material and the water-cooled mold. A voltage-loaded welding wire is fed into the molten pool to carry out electrosurgical melting, and while melting the surface of the core material, a molten metal of a material different from that of the core material is continuously or intermittently added to the molten pool. A method for manufacturing a clad slab, characterized by injecting the same into a clad slab.

In other words, in the method of the present invention, a water-cooled mold is placed around the outer periphery of a core material set vertically, molten slag previously melted in a separate melting furnace is introduced into the gap between the water-cooled mold and the core material, and welding is performed under voltage. Electroslag is melted in a water-cooled mold by continuously feeding a wire, and the molten slag cleans and activates the surface of the core material. After confirming that a certain degree of melting has occurred in the core material, the melting furnace is A clad slab is produced by pouring the pre-melted molten metal that will become the clad material at a constant speed and temperature and solidifying it in a water-cooled mold.

At this time, the water-cooled mold is raised or the core material is lowered so that the molten metal and molten slag that become the cladding material do not flow over the top surface of the water-cooled mold. It can be freely selected by changing the spacing between the core material and the thickness of the core material.

The welding of the cladding material and the core material is controlled by selecting the number (quantity) of welding wires, current and voltage, as well as the molten metal pouring speed and temperature.

One embodiment of the method of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view showing one embodiment of the method of the present invention, and FIG.
The figure is a plan view seen from above. ◇ In Figure 1.2, 1 is the core material that becomes the base material, 2 is the cladding material made of a mixture of melted welding wire 6 and molten metal 5, and 3 is the cladding. A water-cooled mold for forming and solidifying the material 2, 4 is molten slag melted by Joule heat from the welding wire 6, 5 is the molten metal that will become the cladding material, 6 is the welding wire, 7 is a tundish into which the molten metal 5 is poured, 8 is a welding 9 is a welding torch that guides and feeds the wire; 9 is a melting furnace; 10 is a start tab for first forming the clad material; 11 is a feeding device that feeds the wire; 12 is a welding wire coil; 13 is a core material 1
14 is a guide roller for setting the conductive core of the core material.

The method for manufacturing clad slabs is to place the core material 1 of the clad slab on a stand 13 such that the distance between the mold 3 and the core material 1 is a predetermined value.
Set vertically on top of. Next, the core material 1 is raised and set until the start tab 10 welded in advance to the lower end of the core material is in the position of the water-cooled mold 3. Then, molten slag 4 that has been melted in advance is introduced into the gap between the core material 1 and the water-cooled mold 3, and at the same time, a voltage-loaded welding wire 6 is continuously fed to heat the molten slag 4 by Joule heating. heat up.

When the core material 1 is heated and a certain period of time has elapsed, the core material 1 begins to melt due to the Joule heat of the molten slag 4. When the core material 1 is melted to a predetermined depth, the molten metal 15 melted in the melting furnace 9 is poured into the tundish 7. When poured into tandish 7, molten metal 5
flows and is poured into the gap between the core material 1 and the water-cooled mold 3, and the welding wire 6 and the molten metal 5 are mixed and solidified by the cooling effect of the water-cooled mold 3, which becomes the clad material 2. As cladding progresses, welding wire 6 and molten metal 5 melt, and the meniscus of molten slag 4 overflows from water-cooled mold 3. Therefore, it is necessary to raise water-cooled mold 3 or lower core material 1 at regular intervals.

On the other hand, controlling the cladding of the core material 1 is most important for the cladding material. If the penetration is too large, it will be difficult to extract the components of the cladding material, making it impossible to obtain the target components. Furthermore, if the amount of heat is insufficient and the penetration is too small, defects such as poor welding will occur at the boundary.

Melt penetration in the present invention is controlled by selecting the current and voltage applied from the welding wire, the pouring temperature of the molten metal 5, and the pouring speed. At the same time, uneven penetration in the cross-sectional direction is also an important item for cladding materials.The position of the welding wire 6 is changed under one condition and controlled to obtain an appropriate penetration distribution. By rolling the thus produced clad slab to a desired thickness, a clad steel plate can be easily produced.

(Example) Next, an example will be described.

The core material, which is the base material, is 600mm wide and 200mm thick.

A piece of low carbon steel with a length of 5,000 mm was used, and 30 mm thick 5US-308L material was clad around the entire circumference to a length of 4500 mm. The detailed shilading conditions at this time were as shown in Table 1, and the cladding speed was 30 mrrI/rr11o when pouring the molten metal.

As a result, the penetration of the core material was almost uniform over the entire circumference and length, the penetration depth was about 1 to 3 mm, the welding was complete, and no defects such as slag bite occurred.

FIG. 3 is a microscopic micrograph of the structure near the boundary of the material constructed in this example. This shows that the welding at the boundary is also metallurgically complete.

FIG. 4 is an EPMA analysis of the vicinity of this boundary, and the mixed layer at the boundary is about 50 μm. Furthermore, it can be seen that the components change smoothly with no component segregation near the boundary.

FIG. 5 shows a side bending test conducted on the material after hot rolling. The test was a macro photograph after bending at 180 degrees, and it was possible to create a product with sufficient contact strength at the boundary without any peeling from the boundary. Compared to conventional methods, this method is easier to manufacture and the manufacturing cost is lower because it is composited at the casting stage. Furthermore, compared to other cast rolling methods, it is possible to freely control the ratio of cladding material, the yield is high, the welding condition at the boundary is good, and it is possible to produce products that are superior to conventional methods in terms of cost and quality.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing one embodiment of the system of the present invention, and FIG.
Figure 3 is a plan view of the method of this invention, Figure 3 is a microscopic organizational diagram of the area near the boundary of the product manufactured using the method of this invention, and Figure 4 is an EPMA diagram of the area near the boundary of the item manufactured using the method of this invention.
FIG. 5 is a diagram showing the results of a side bending test after hot rolling a product manufactured by the method of the present invention. ■・・・Core material 2...Clad material 3...
Water-cooled cold 4... Molten slag 5... Molten metal
6...Welding wire 7°°° tundish
8...? IW)-chi9...Wj solution P t
o...Start tab 11...Wire feeding device 1
2... Welding wire coil 13... Frame
14...Guide roller Applicant Nippon Steel Corporation Figure 1 Whistle 2 Procedure amendment (method) February 3, 1985 Patent application No. 239184 2, filed in 1985 Title of invention Clad slab Manufacturing method 3, Relationship with the case of the person making the amendment Patent applicant address: 2-6-3 Otemachi, Chiyoda-ku, Tokyo (665
) Nippon Steel Corporation Name Representative Takeshi 1) Yutaka 4, Agent 〒1
03. 241-04415゜ Date of amendment order January 28, 1985 (Shipping date) 6. Column for brief explanation of the drawings of the specification subject to amendment and Drawing 7 Contents of amendment 1) Page 10, line 12 of the specification In line 13, "micrograph micrograph organization chart" is corrected to "micrograph micrograph of metallographic structure."

Claims (1)

[Claims] A core material with a rectangular horizontal cross section is set vertically on a stand, a water-cooled mold is placed around its outer periphery, and a voltage-loaded welding wire is fed into the molten pool in the gap between the core material and the water-cooled mold. . A method for producing a clad slab, characterized by performing electroslag melting and continuously or intermittently injecting molten metal of a material different from that of the core material into the molten pool while melting the surface of the core material.